It's not smooth but I think you should be ok

I’d shop around for a tour guide as the site works in partnership with Antalya Museum (where many of the funds are displayed) and one of the local universities. We used U Can Travel (with an office in Antalya) and their guide was a Professor from the university, providing a historical tour of Perge, Aspendos and Side.

Если Вы добираетесь до Перге своим ходом от города Аксу, дорога идет перпендикулярно шоссе на Анталию и, кажется, называется Перге ела. Там находится не очень большая мечеть с Минаретом. В Самом Перге открытая площадка - музей!

You questions have pretty much been mostly answered but I did want to clear up the issue with the Colosseum being closed for years. It is actually open for touring and it is by far one of the best preserved Greco-Roman theater's in the world. Exploring by foot is necessary but the path's and roads are not difficult to walk on. On a scale of 1 to 10, 10 being the most difficult to navigate by foot, I would estimate that Perge would rate around a 2 to 3. Two hours would be a decent amount of time to explore as long as you're not a budding archaeologist.

Emanet odası, kilitli dolap gibi hizmetler yok. Bilet satışı yapılan gişedeki görevliler yardımcı olabilir.

Sí las carreteras son buenas y hay aparcamiento

Интересны оба города. И посмотреть стоит оба. Но для Термессоса вам понадобится больше времени, больше здоровья, так как нужно походить, да еще и в гору. Ну и одеться поудобнее.

Да, амфитеатр открыт для осмотра.

the tram to the expo has a stop called 'aksu 1'. From there it is a 20min walk to the ruins. We purchased the transport antalya card from a mobile phone shop and you use that on the tram. It was very hot on the 20 min walk, but it was hotter inside the site.Taxi from old city quotes 90 TL which we paid to get there because I did not know the tram went so close. Returned to the city on the tram which has a stop very close to the old city when it returns

Las entradas a Perge las pagamos allá, en el ingreso. Igual que en casi todos los paseos, como Troya o Efeso.... No pagamos nada de eso desde Argentina. No sé si les sirve la respuesta!!! Es hermosísimo Perge y no dejen de ir a Aspendos que no es lejos y es un muy hermoso anfiteatro, muy bien conservado